Copper layer thickness for 325 MHz superconducting cavity input couplers

This article studies the relationship between the copper layer thickness of the outer conductor of superconducting cavity input coupler and the heat leak.We compared copper coatings of 10，20，30 m respectively of 325 MHz coupler through high power test and aimed to find the optimum thickness of the copper plating layer in order to decrease the cryogenic heat load . The experimental results show that 20 m layer has lower dynamic heat leak. Considering both static heat leak and dynamic heat leak, the 20 m thickness of copper layer is the optimum one.